An activation tagging screen in which the cauliflower mosaic virus 35S enhancer was inserted randomly into an Arabidopsis genome homozygous for the floral homeotic mutation apetala2-1 (ap2-1) resulted in a line (28-5) with extraordinarily wide, heart-shaped ovaries. The ovary of the 28-5 ap2-1 mutant shows an oval shape because of increased numbers of enlarged cells. When the ap2-1 mutation is ...

Self-incompatibility (SI) is a major obstacle for stable fruit production in fruit trees of Rosaceae. SI of Rosaceae is controlled by the S locus on which at least two genes, pistil S and pollen S, are located. The product of the pistil S gene is a polymorphic and extracellular ribonuclease, called S-RNase, while that of the pollen S gene is a protein containing the F-box motif, SFB (S haplotyp...

A newly recovered twig with attached leaves and flowers from the Eocene Green River Formation of Utah provides the basis for recognizing a new, extinct genus of Salicaceae sensu lato (s.l.). Pseudosalix handleyi gen. et sp. nov. has alternate lanceolate leaves with pinnate, semicraspedodromous venation and a serrate margin with glandular teeth. The inflorescence is terminal on the twig and is u...

soil affected by salt (nacl) is a major problem worldwide and in areas with potential agriculture; lands in many countries are not enough to support crop production. the development of salt tolerant cultivars would be enhanced by better understanding of the genetic control of tolerance to salt stress. a new cereal, tritipyrum, a range of amphiploids between triticum spp. and thinopyrum spp....

Extreme year-to-year variability in yield is a major concern for Arkansas cotton farmers. This variability has been partially explained by year-to-year variation in average maximum temperature during flowering. For example, heat stress (average maximum temperatures near 95 °C) during flowering experienced by cotton plants during a typical growing season in the U.S. is a major cause of disappoin...

Differentiation of female sexual organs in flowering plants is rare and contrasts with the wide range of male reproductive strategies. An unusual example involves diplostigmaty, the possession of spatially and temporally distinct stigmas in Sebaea (Gentianaceae). Here, the single pistil within a flower has an apical stigma, as occurs in most flowering plants, but also a secondary stigma that oc...

The generation of novel hybrid lines is critically limited by the compatibility between pollen and pistil and their ability to achieve successful seed formation. Fertilization in flowering plants requires the successful transfer of the male gametes from the pollen grain to the egg contained within an ovule. This occurs via the formation of a tubular protrusion from the pollen grain – the pollen...

In flowering plants, immotile sperm cells develop within the pollen grain and are delivered to female gametes by a pollen tube. Upon arrival at the female gametophyte, the pollen tube stops growing and releases sperm cells for successful fertilization. Several female signaling components essential for pollen tube reception have been identified; however, male components remain unknown. We show t...

Most chrysanthemum cultivars are self-incompatible, so it is very difficult to create pure lines that are important in chrysanthemum breeding and theoretical studies. In our previous study, we obtained a self-compatible chrysanthemum cultivar and its self-pollinated seed set was 56.50%. It was interesting that the seed set of its ten progenies ranged from 0% to 37.23%. Examination of the factor...